The present invention relates to a buckle for swimming/diving goggles and, more particularly, to a buckle for swimming/diving goggles allowing easy adjustment of a length of a head strap.
Swimming goggles generally include two lenses, two frames, a bridge, a buckle, and a head strap. The buckle allows adjustment of a length of the head strap. FIG. 8 shows a conventional buckle 1′ including an end with an engagement portion 11′ for engagement with a body 3′ of a pair of swimming goggles. The other end of the buckle 1′ includes a coupling portion 12′ for coupling with a soft head strap 2′. The coupling portion 12′ includes pegs 121′ and 122′ at an intermediate portion thereof. A notch 123′ is defined in a front end of the coupling portion 12′. The head strap 2′ is extended between the notch 123′ and the peg 121′ and wound around the pegs 121′ and 122′ and extended between the notch 123′ and the peg 121′ again, fixing the head strap 2′. When adjustment of the head strap 2′ is required, the user removes the body 3′ from his or her head, loosens the head strap 2′, and adjusts the length of the head strap 2′, which is troublesome and time-consuming. However, the length of the head strap 2′ after adjustment may not fit the head of the user. As a result, readjustment of the head strap 2′ is required when the head strap 2′ is either too tight or too loose. Furthermore, the head strap 2′ deforms significantly at the bends wound around the pegs 121′ and 122′.
FIG. 9 shows another pair of conventional swimming goggles including a pressing portion 4′, a clamping portion 5′, and a connecting portion 6′. The pressing portion 4′ includes a post 41′ around which a head strap 7′ extends. The clamping portion 5′ includes a clamping hole 51′ and a retaining edge 52′. The head strap 7′ is extended through the clamping hole 51′ and retained by the retaining edge 52′. Thus, the head strap 7′ can only extend around the post 41′ without significant deformation. An end of the head strap 7′ can be pulled to retain the head strap 7′ by the post 41′ and the retaining edge 52′. A user can push the pressing portion 4′ towards the post 41′ to increase the spacing between the post 41′ and the retaining edge 52′, as indicated by the double arrow, allowing loosening of the head strap 7′. In another approach, the user can push the pressing portion 4′ outward to increase the spacing between the post 41′ and the retaining edge 42′, allowing loosening of the head strap 7′, as shown in FIG. 10. An example of such a buckle is shown in U.S. Pat. No. 6,691,378 (Taiwan Utility Model No. 218191). However, the force for pushing the pressing portion 4′ in either approach must be larger than the clamping force of the head strap 7′, such that the hand of the user pushing the pressing portion 4′ is liable to slip, failing to provide easy, convenient operation.